Polybasic acid ester of higher alcohols



Patented Sept. 24, 1935' UNITED STATE s PATENT OFFICE POLYBASIC ACID ESTER OF HIGHER- ALCOHOLS Ebenezer Emmet Reid,

Baltimore, Md., assignor to E. I. du Pont'de Nemours & Company, Wilmington, Del., a corporation of Delaware No Drawing. Application October 14, 1932, Serial No. 637,784

11 Claims.

six carbon atoms.

containing at least six carbon atoms, or by reacting sodium salts of the acids with chlorides or other'halide esters of the alcohols under suitable conditions or by ester interchange of these alcohols with esters of more volatile alcohols.

The following examples which are illustrative only, typify the methods used in the preparation of these esters.

Example 1 A mixture of alcohols boiling above 160' 0., all of which have a branched carbon chain structure and which were obtained in the catalytic synthesis of methanol from C0 and H2, which mixture contains various amounts of the following alcohols: 2,4,dimethyl-l-pentanol, 4-methyll-hexanol, 2,4,dimethyl-l-hcxanol, 5-methy1-1- heptanol, 4,6,dimethyl-1-heptanol, 2,6,dimethyl-1-- octanol, 2,4,6,trimethyl-l-octanol, 2-et'nyl-4-6- dimethyl- 1 -octanol, 2,4,6,trimethyl- 1 -decanol, 2,4,6,8,tetramethyll-decanol, 3-methyl-2-hexa nol, 3-methyl-2-heptanol, 5-methyl-3-octanol, 3- ethyl-2-nonanol, etc. may be used in the preparation of a. neutral phthalate as follows: A mixture containing 400 grams phthalic anhydride, 780 grams of the above alcohols, 200 grams toluol, and 10 grams-sulfuric acid, is heatedin an apparatus designed to separate water from the distillate and to return the toluol to the reaction ask. Distillation is continued until the theoretical amount of water has been removed. The products is washed with sodium carbonate solution to remove the acid and is then refined by heating under vacuum in the presence of decolorizing carbon until the temperature reaches approximately 180 C. at mm. The product is filtered to remove the carbon and is then ready for use. The product as above prepared comprises a mixture of phthalic esters in which at least one carboxyl group has been esterified by the branched carbon-chain alcohols in the mixture. Such an ester mixture is useful as a plasticizer for cellulose nitrate and cellulose ether compositions.

Example 2 A benzene solution of mixed alcohols (obtained from the methanol synthesis) boiling above (the composition of which is essentially the same as the mixture used in Example 1 and containing in addition Z-methyl-l-pentanol) is mixed with an equimolar proportion of phthalic anhydride and heated overnight in a steam bath. The solution is then cooled to 5 to 10 to precipitate unchanged phthalic anhydride which is filtered off. The benzene solution is then extracted with 5 10% sodium hydroxide solution in an amount equivalent to the phthalic anhydride which is reacted. After the alkali and benzene have been thoroughly mixed they are allowed to separate. The lower or aqueous layer contains the sodium salts of the acid phthalate ester of the primary alcohols contained in the original mixture, while the upper layer contains the secondary alcohols dissolved in benzene. The acid ester may be obtained by the addition of mineral acid to the aqueous solution.

Example 3 A mixture containing the above acid phthalate ester prepared as described in Example 2 and butyl alcohol in equal molar proportions is dissolved in toluol with the addition of a small amount of sulfuric acid as a catalyst and heated in an apparatus described in Example 1. After removal of the theoretical amount of water, the 3 product is refined as in Example 1. The resultant product is a mixed butyl higher alcohol ester of phthalic acid.

Example 4 A mixture containing grams phthalic anhyl-octanol, 2-ethyl-4-6-dimethyl-l-octanol, 2,4,6, 55

. one may use secondary alcohols including those commonly found in higher alcohols from the' methanol synthesis, such as 2-methyl-3-pentanol, 3-methyl-2 -pentanol, 2,4,dimethyl-3rpentanol, 3, 4,dimethyl-2-pentanol, 3-methyl-2-hexanol, 3- methyl-z-heptanol, 5-methyl-3-octanol, 3-ethyl- 2-nonanol, etc.

In preparing the mixture of alcohols, the use of which is described in Example 1, by way of catalytic synthesis from carbon monoxide and hydrogen, this mixture of alcohols, due,to the nature of the methanol synthesis reaction, contains in association therewith, numerous organic compounds other than alcohols, which for the most part contain oxygen in substantial amounts. This fact is readily recognized from the knowledge possessed by the art regarding the nature of the products produced during the methanol synthesis. The scope of the invention contemplates the use of these crude alcoholic mixtures in preparing esters of the character described.

The esters prepared as above described are all liquids varying from water-white to light amber in color, depending on their purity. They are high boiling and quite compatible with cellulose derivatives. In fact, they are more desirable for use with cellulose derivatives than similar esters prepared from straight chain normal alcohols of the same molecular weight. Although Examples 1 to :1 include only 'phthalic acid and phthalic anhydride, any polycarboxylic acid may be used including adipic, suocinic, sebacic, citric, tartaric, trimesic, quinolinic, hexahydrophthalic, tetrahydrophthalic, etc.

The esters of the present invention may be used as plasticizers with cellulose derivatives such as cellulose nitrate, cellulose acetate, cellulose propionate, cellulose butyrate, cellulose aceto-' butyrate, cellulose nitroacetate, and other cellulose esters, ethyl cellulose, benzyl cellulose, and other cellulose ethers, with or without resins such as damar, ester gum, polyhydric alcoholpolybasic acid resins, and the like, and oils such as castor, Chinawood, linseed, soya bean, cottonseed oil, and the like, and pigments. Additional plasticizers known to the art such as triacetin, triphenyl phosphate, dibutyl phthalate, camphor, tricresyl phosphate, and the like, and solvents such as alcohols for cellulose nitrate compositions, acetone for cellulose acetate compositions, and toluol-alcohol for cellulose ethers may likewise be used.

The compounds herein disclosed may likewise be used as plasticizers and/or softeners for natural resins such'as damar, sandarac, Congo, elemi, guaiac, kauri, rosin, etc., and synthetic resins such as polyhydric alcohol-polybasic acid resins (glyptals), phenol-aldehyde resins, urea-formaldehyde resins, vinyl resins, ester gums, etc. They may be used alone or in conjunction with other modifiers for the resin, such as waxes, etc. The method of preparation of the compounds described above is capable of considerable variation. In the esteriflcation reaction catalysts other than those mentioned may be used. Solvents other than those mentioned may be used to remove the water. In some cases solvents may be used without the use of a catalyst, and in still other cases neither solvent nor catalyst may be used. Also one may react a chloride or simple ester of the acid with the branched chain primary alcohols or the chloride of the alcohol with asalt of the acid undersuitable conditions. The term polycarboxylic acid ester of branched carbon chain primary alcohols containing at least six carbon atoms" as used herein is intended to apply tocompounds having the following nucleus:

V The term branched carbon open-chain alco-' hol" is intended to apply to open-chain alcohols,

the carbinol group of which is attached to a branched carbon radical. The alcohols within this class with which the invention is most particularly concerned are those having from six to fourteen carbon atoms.

The novel esters may be used in the preparathe preparation of lacquers for coating metal and wood, dopes for coating fabrics, moistureproof lacquers for coating regenerated cellulose, and in plastic compositions to be used in the preparation of toiletwarenovelties, sheeting, rods, tubes, safety glass interlayer, etc.

The advantage of this invention is that it furnishes high boiling, water-resistant plasticizers for cellulose derivatives, and due to their low vapor pressure they give permanently flexible products having good durability. These compounds are characterized by being more satisfactory plasticizers for cellulose derivatives than compounds prepared from straight chain normal alcohols of the same molar weight. For example, the di-phthalate of 2,4-dimethyl hexanol-l gives a good water-resistant coating when used as a plasticizer for cellulose nitrate, and the composition does not have a greasy feel, whereas di-noctyl phthalate, although giving a good water- -resistant composition when used as a plasticizer of the invention is intended to be included within the scope of the claims.

I claim:

1. A mixture of poly-carboxylic acid esters con- 'one,saidmixedestersbeingpreparedfromamixhum No. 2,015,083. V

ture containing largely primary branch chain alcohols of six to fourteen carbon atoms.

2. A mixture of poly-carbonlicacid esters containing the following nucleus:

in which R is a polyvalent radical, and m is a saturated branched carbon open-chain primary alkyl radical containing at least six carbon atoms and :z: is at least one, said mixed esters being prepared from a mixture containing largely primary branch chain alcohols of six to fourteen carbon atoms.

3. A mixture of poly-carboxylic acid esters containing the following nucleus:

inwhichRisapolyvalentradical,andR1isthe radical, of a branched carbon open-chain pri-- mary alcohol having at least six carbon atoms and :r is atleast one, said mixed esters being prepared from a mixture of alcohols prepared by the catalytic hydrogenaiton of carbonic oxides at-an elevated temperature and pressure.

5. a mixture of phthalic esters obtainable by heating a mixture comprising phthalic anhydride;

and mixed alcohols boiling above 135 C., said mixed alcohols beingobtainedby the hydrogena- EBENEZER EMMET. REID.

tion of carbon oxide at an elevated temperature and pressure.

6. An ester of a polycarboxylic acid wherein the hydrogen atom of at least one carboxyl group is replaced by the radical of a saturated branched carbon open-chain primary alcohol containing six to fourteen carbon atoms, said alcohol being obtainable by the catalytic hydrogenation of carbon oxides and being taken from the class consisting of 2,4,dimethyl -l-pentanol, 2-methyl-l-hexanol, d-methyl-l-hexanol, 2,4,dimethyl-l-hexanol, S-methyl-l-heptanol, 4,6,dimethyl-1-heptanol, 2,6,dimethyl-l-octanol, 2,4,6,trimethyl-1-octanol, 2-ethyl-4-6t-dimethyl-l-octanol, 2,4,6,trimethyll-decanol, 2,4,6,8,tetramethyl-l-decanol, and 2- methylpl-pentanol. 7. An ester of a dicarboxylic acid wherein the hydrogen atom of at least one carboxyl group is replaced by the radical of a saturated branched carbon open-chain primary alcohol containing six to fourteen carbon atoms, said alcohol being obtainable by the catalytic hydrogenation of carbon oxides and being taken from the class consisting' of 2,4,dimethyl-1-pentanol, Z-methyl-lhexanol, .-methyld-hexanol, 2,4,dimethyl-1- hexanol, 5-methyl-1-heptanol, 4,6,dimethy1-lheptanol. 2,6,dimethyl-1-octano1, 2,4,6,trimethyll-octanol, 2-ethyl-4-6-dimethyl-l-octanol, 2,4,6,- trimethyl l-decanol, 2,4,6,8,tetramethyl-l-decanol, and z-methyl l-pentanol.

8. An ester of'phthalic acid wherein the hydro gen atom of at least one carboxyl group is replaced by the radical of a saturated branched carbon open-chain primary alcohol containing six'to fourteen carbon atoms, said alcohol beingu V o ,tainable by theratalytic hydrogenation of carn oxides and being taken'from the class consistingaif2,4,dimethyl-l-pentanol, 2-methyl-lhexanol 'A-methyl-l-hexanoL 2,4,dimethyl-lhexanol, S-methyid-heptanol, 4,6,dimethyl-1- heptanol. 2,6,dimethyl- -octanol, 2,4,6,trimethyl- 1-'-octano l; 2-ethyl-4-6-dimethyl-1-octano1, 2,4,6,- trimethyl-l-decanol, 2,4,6,8,tetramethyl-'l-decanol, and 2 -methyl -1-pentanol.

9'. A 2-methyl-nwamyl-phthalate.

10. A 2-methyl-n-hexyl phthalate.

11. A 5-methyl n-heptyl phthalate.

CERTIFICATE OF connection.

September 24, 1935.

[t is hereby certified that error appears in the printed specification of the I above numbered patent requiring correction as follows:

Page 1. first column,

I a line 44 for "ask" read flask; and that the said Letters Patent should be read in the Patent Office. I Signed and sealed this "19th day of November, A. 1935.

with this correction therein that the same may conform to the record of the Leslie Frazer Acting. Comissioner of Patents.

'one,saidmixedestersbeingpreparedfromamixhum No. 2,015,083. V

ture containing largely primary branch chain alcohols of six to fourteen carbon atoms.

2. A mixture of poly-carbonlicacid esters containing the following nucleus:

in which R is a polyvalent radical, and m is a saturated branched carbon open-chain primary alkyl radical containing at least six carbon atoms and :z: is at least one, said mixed esters being prepared from a mixture containing largely primary branch chain alcohols of six to fourteen carbon atoms.

3. A mixture of poly-carboxylic acid esters containing the following nucleus:

inwhichRisapolyvalentradical,andR1isthe radical, of a branched carbon open-chain pri-- mary alcohol having at least six carbon atoms and :r is atleast one, said mixed esters being prepared from a mixture of alcohols prepared by the catalytic hydrogenaiton of carbonic oxides at-an elevated temperature and pressure.

5. a mixture of phthalic esters obtainable by heating a mixture comprising phthalic anhydride;

and mixed alcohols boiling above 135 C., said mixed alcohols beingobtainedby the hydrogena- EBENEZER EMMET. REID.

tion of carbon oxide at an elevated temperature and pressure.

6. An ester of a polycarboxylic acid wherein the hydrogen atom of at least one carboxyl group is replaced by the radical of a saturated branched carbon open-chain primary alcohol containing six to fourteen carbon atoms, said alcohol being obtainable by the catalytic hydrogenation of carbon oxides and being taken from the class consisting of 2,4,dimethyl -l-pentanol, 2-methyl-l-hexanol, d-methyl-l-hexanol, 2,4,dimethyl-l-hexanol, S-methyl-l-heptanol, 4,6,dimethyl-1-heptanol, 2,6,dimethyl-l-octanol, 2,4,6,trimethyl-1-octanol, 2-ethyl-4-6t-dimethyl-l-octanol, 2,4,6,trimethyll-decanol, 2,4,6,8,tetramethyl-l-decanol, and 2- methylpl-pentanol. 7. An ester of a dicarboxylic acid wherein the hydrogen atom of at least one carboxyl group is replaced by the radical of a saturated branched carbon open-chain primary alcohol containing six to fourteen carbon atoms, said alcohol being obtainable by the catalytic hydrogenation of carbon oxides and being taken from the class consisting' of 2,4,dimethyl-1-pentanol, Z-methyl-lhexanol, .-methyld-hexanol, 2,4,dimethyl-1- hexanol, 5-methyl-1-heptanol, 4,6,dimethy1-lheptanol. 2,6,dimethyl-1-octano1, 2,4,6,trimethyll-octanol, 2-ethyl-4-6-dimethyl-l-octanol, 2,4,6,- trimethyl l-decanol, 2,4,6,8,tetramethyl-l-decanol, and z-methyl l-pentanol.

8. An ester of'phthalic acid wherein the hydro gen atom of at least one carboxyl group is replaced by the radical of a saturated branched carbon open-chain primary alcohol containing six'to fourteen carbon atoms, said alcohol beingu V o ,tainable by theratalytic hydrogenation of carn oxides and being taken'from the class consistingaif2,4,dimethyl-l-pentanol, 2-methyl-lhexanol 'A-methyl-l-hexanoL 2,4,dimethyl-lhexanol, S-methyid-heptanol, 4,6,dimethyl-1- heptanol. 2,6,dimethyl- -octanol, 2,4,6,trimethyl- 1-'-octano l; 2-ethyl-4-6-dimethyl-1-octano1, 2,4,6,- trimethyl-l-decanol, 2,4,6,8,tetramethyl-'l-decanol, and 2 -methyl -1-pentanol.

9'. A 2-methyl-nwamyl-phthalate.

10. A 2-methyl-n-hexyl phthalate.

11. A 5-methyl n-heptyl phthalate.

CERTIFICATE OF connection.

September 24, 1935.

[t is hereby certified that error appears in the printed specification of the I above numbered patent requiring correction as follows:

Page 1. first column,

I a line 44 for "ask" read flask; and that the said Letters Patent should be read in the Patent Office. I Signed and sealed this "19th day of November, A. 1935.

with this correction therein that the same may conform to the record of the Leslie Frazer Acting. Comissioner of Patents. 

